56759-32-1Relevant articles and documents
A Practical Procedure for Regioselective Bromination of Anilines
Takahashi, Yusuke,Seki, Masahiko
, p. 1828 - 1832 (2021/04/15)
A highly practical procedure for the preparation of bromoanilines by using copper-catalyzed oxidative bromination has been developed. Treatment of free anilines with readily available NaBr and Na 2S 2O 8in the presence of a catalytic amount of CuSO 4·5H 2O enabled regioselective bromination.
Phenylethanolamine β receptor agonist synthetic method
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Paragraph 0051-0054, (2019/07/04)
The invention discloses a phenylethanolamine β receptor agonist synthetic method, comprises the following steps: S1: the 4 - amino acetophenone dissolved in an organic solvent, with the electrophilic reagent occurs on the benzene ring substituted halogenated reaction, generating [...] intermediate; [...] intermediates in organic solvent or in water, under the catalysis of the metal catalyst with the cyanide reagent undergo nucleophilic substitution reaction, generating phenyl ketone intermediate; S2: phenyl ketone intermediates in organic solvent, with the copper bromide generating carbonyl α bromo reaction to produce α - bromoacetophenone intermediates; S3: α - bromoacetophenone intermediates in organic solvent with tert-butyl amine or isopropylamine reaction intermediates acetophenone amines; S4: acetophenone amine intermediates in organic solvent, with the reduction hydrogenation reagent react to generate the phenylethanolamine β receptor agonists; synthetic method of this invention a simple and highly efficient and cheap and easy to obtain, atom utilization is high, the synthetic product chemical purity is greater than 99%, to meet the detection requirements of the food safety.
Reducing Diastereomorphous Bis(phosphane oxide) Atropisomers to One Atropisomerically Pure Diphosphane: A New Ligand and a Novel Ligand-Preparation Design
Sartorius, Frank,Trebing, Marc,Brückner, Charlotte,Brückner, Reinhard
supporting information, p. 17463 - 17468 (2017/11/27)
1,1′-Biphenyl-2,2′-diphosphanes with an achiral bridge spanning C-5 and C-5′ form atropisomers that are enantiomers. Accessing them in an atropisomerically pure form requires resolving a racemic mixture thereof or of a bis(phosphane oxide) precursor. 1,1′-Biphenyl-2,2′-diphosphanes with a homochiral bridge spanning C-5 and C-5′ form atropisomers that are diastereomers. We synthesized the first compound of this kind 1) atropselectively and 2) under thermodynamic control—seemingly a first-time exploit in diphosphane synthesis. The selectivity-inducing step was a high-temperature reduction of two non-interconverting bis(phosphane oxide) atropisomers (60:40 mixture). It furnished the desired diphosphane atropisomerically pure (and atropconvergently because the yield was 67 %). This diphosphane proved worthwhile in Tsuji–Trost allylations, the Hayashi addition of phenylboronic acid to cyclohexenone, and the asymmetric hydrogenation of methyl acetoacetate (up to 95 % yield and 95 % ee).